Solid bleach composition and method of making and using same



United States Patent of Delaware No Drawing. Filed Apr. 20, 1955, Ser. No. 502,722

I 6 Claims. (Cl. 25299) This application is a continuation-in-part of US. application S.N. 421,452, filed April -6, 1954, now abandoned.

This invention relates to a composition of matter useful for bleaching or for bleaching and detergent purposes and to methods for preparing and using same, particularly in the treatment of textile materials such as textile fabrics and the like.

In accordance with the present invention, the composition comprises a 1,3-dich1oro-dialkylhydantoin, preferably 1,3-dichl'oro-5,5-dimethylhydantoin, in a proportion suflicient to exert a distinct bleaching function, and at least about 10% by weight of the entire composition of material from thegroup of water-soluble molecularly dehydrated alkali metal phosphate salts, alkali metal silicates and fully neutralized alkali metal carbonates. Preferably an organic detergent also is present in a proportion sufficient to exert a solubilizin g and wetting action, and advantageously sufiicient to exert also a cleaning function. Where the composition is intended for use in the bleaching and cleaning of textile materials it is important that the initial pH of aqueous solutions thereof be at least about 7.5 to prevent tendering of textile fibres treated there-in with consequent loss in tensile strength and durability. Other ingredients which do not substantially detract from the properties of the composition containing the recited ingredients, e.g., fillers such as sodium sulfate and sodium chloride, or ingredients which exert a beneficial effect upon the composition, e.g., butters such as trisodium phosphate which assist in control of pH, soil suspending agents such as sodium carboxymethyl cellulose, organic builders, optical ble'aches, dyes, pigments,

- and like additives may be, and in some cases preferably are, present.

The termmolecularly dehydrated phosphate salts.is

-metal carbonates is used herein to define carbonates in which both valen'ces of the carbonate radical are satisfied by alkali metal atoms, e.g., Na CO as opposed to the partially neutralized or acid carbonates, e.g., NaHOO In its broadest aspect, the composition of the present invention comprises a 1,3-dichloro-5,5-dialkylhydantoin, e.g., within a range of about 1% to 30%, in admixture with other suitable materials which must include at least one of the materials of said group in a proportion of at least about 10% by weight of the entire composition. Viewed in somewhat more narrow aspect, the composition advantageously comprises from about 1 to 25%, and preferably from about 5 to 15%, of the dichloro-dialkylhydantoin ingredient, about 60 to 97% of alkali metal salts including neutral salts and inorganic builders as well as at least of at least one salt from said group, and the balance is made up of various wetting and surface active agents including, if desired, small amounts of pigments, dyes, organic additives and/or optical bleaches. When the composition is prepared in the form of a very finely divided powder, it may also be desirable to incorporate therein a fraction (up to 1%) of a highly refined 3,257,3'24' Patented June 21, 1966 cient strength to prevent crushing under normal conditions of packaging, shipping, etc. The latter form of product indeed is preferable to the extremely fine material which during use tends to dust to an objectionable degree. When employing the tumbling method in the presence of moisture, as just mentioned, the moisture may be added in any desired manner but preferably is supplied via atomization of water.

Compositions embodying the present invention possess a number of advantages. Among the outstanding properties of such compositions are their ability to remove stains such as ink, coffee and like stains on fabrics, food stains on enamel sin-ks, tarnish stains on metals such as copper, stains which form on porcelain toilet bowls, and the like; their ability to preserve or retain whitness of cotton on repeated bleaching treatment; their case of storage and use; and their versatility for such multiple uses as a complete washing composition for clothes, particularly in automatic type washing machines, a bleaching rinse, a metal cleaner, a toilet bowl cleaner, a kitchen sink cleaner, and other like uses, and as a growth inhibitor for algae in water tanks, and the like.

Tests demonstrate that the combination of properties possessed by the compositions of the present invention depends critically upon the presence inthe composition ofbenzene sulfonate, 4.5% sodium toluene sulfonate, 53.3%

of sodium sulfate and 30% of various inorganic sodium salts are used to wash a plurality of cotton swatches for 10 cycles. Each cycle consists of a 20 minute wash at F. in a -Tergometer in tap water (about 50 ppm. hardness) at 2.3 grams of each composition per liter, a rinse in warm tap water for 3 minutes and drying by ironing. After 10 cycles the cotton swatches are evaluated visually for preference and also on a Hunter color difference meter. Compositions containing tetrasodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate, sodium carbonate and sodium silicate give significantly higher whiteness (visual preference and higher percent White by the meter) and lower yellowness than compositions containing other alkaline salts such as sodium bicarbonate, trisodium phosphate or borax as the sodium salt content. Similar tests on compositions in which the content of inorganic sodium salt from said group (tetrasodium pyrophosphate, for example) varies from O to 30%, the difference being made up with sodium sulfate, show a significant improvement at 10% over 0% and a somewhat greater efiect within the range of about 20% to 30% of the said phosphate salt. Proportions of the salts specified higher than 30% give highly satisfactory results also and there are increased performance benefits under certain conditions from the higher proportions of the phosphate salts, although for economic reasons it may be desirable to use some inorganic filler such as sodium chloride and sodium sulfate. For this reason it is generally preferred to employ one or more of the salts from the group in a total proportion of about 20 to 50% by weight of total solids and to use less expensive alkaline or neutral inorganic salts such as sodium chloride, sodium sulfate, borax and the like to make upthe balance of the composition.

The best compositions, from a cost and performance standpoint in the uses mentioned, contain tetrasodium pyrophosphate within the range of about 20% to 40% by weight of total solids. The following Examples I through VIII are given of compositions containing tetrasodium pyrophosphate within the preferred range by way of illustration and without intending any limitation upon the scope of the invention except as defined in the claims set forth hereinafter. All parts are by weight here and elsewhere unless otherwise indicated by the context.

Example I A composition is made up having the following ingredients:

' Percent 1,3-dichloro-5,S-dimethylhydantoin 14.7 Wetting agent (an alkyl aryl sulfonate that achieves a quicker and better dispersion and dissolution of the particles of the bleach composition; more particularly, a mixture of monobutyl and dibutyl naphthalene sodium sulfonates) 5.9 Sodium sulfate 29.4 Sodium chloride 23.5 Tetrasodium pyrophosphate 23.5 Foaming and emulsifying agent (an alkyl aryl sulfonate which adds foaming and emulsifying properties to the composition; more particularly, a roll-dried sodium dodecyl benzene sulfonate wherein the source of the alkyl group is propylene tetramer) 2.9 Fluorescent dye (a bleach-stable commercially available optical dye or bleach of the type shown in Scalera US. Patent No. 2,563,493 of which the' following structural formula is typical 0.1

The foregoing components are mechanically mixed in dry form and are then pulverized in a mill to .a particle size varying from about 2 to 90 microns, with over 90% of the composition consisting of particles in the range between 5 and 30 microns.

The finely divided composition thus obtained shows good solubility in water and an available chlorine content of about 9.2%. Tests show that this bleach composition is very effective in cleaning and removing stains.

Towel tests performed upon towels soiled by workmen employed in a railroad maintenance shop show that this composition is extremely effective in respect of its total washing power, its low soil redeposition qualities, and the whiteness or bleaching effect of the optical dye contained therein, while at the same time having no adverse effect upon the tensile strength of the fabric. The towel tests are -run using 0.25% by weight of a commercially available sodium alkyl aromatic sulfonate synthetic detergent dispersed in tap water, having about 30 to 50 parts per million hardness as CaCO the solid bleach composition of the present invention being added duringthe wash cycle.

The foregoing bleach composition is also found to be very stable on standing, accelerated aging tests under conditions of 90% relative humidity and 90 F. revealing only relatively minor (i.e., from to 30%) losses of available chlorine content after four weeks exposure to same.

The pH of the aqueous solution obtained with the composition of this example is in excess of 9;

The foregoing ingredients are mixed, ground and employed as described above in Example I, with substantially comparable results as regards stability, washing and bleaching action.

Example III Percent 1,3-dichloro-5,5-dimethylhydantoin 14.7 Sodium dodecyl benzene sulfonate 2.9 Wetting agent (same as Example I) 5.9 Tetrasodium pyrophosphate 20.0 Sodium carbonate (anhydrous) 20.0 Optical dye (same as Example I) 2.15 Sodium sulfate (anhydrous) 36.35

The foregoing ingredients are mixed, ground and employed as described above in Example I, with substantially comparable results as regards stability, washing and bleaching action.

Example IV Percent 1,3-dichloro-5,S-dimethylhydantoin 14.7 Sodium dodecyl benzene sulfonate 2.9 Wetting agent (same as Example I) 5.9

Tetrasodium pyrophosphate (anhydrous) 23.5

OCH;

Sodium carbonate (anhydrous) 10.0

Sodium chloride 13.5 Sodium sulfate (anhydrous) 29.5

The foregoing ingredients are mixed, ground and employed as described above in Example I, with substantially comparable results as regards stability, washing and bleaching action.

Example V Percent 1,3-dichloro-5,S-dimethylhydantoin 14.7 Sodium isopropyl naphthaline sulfonate 5.9 Sodium sulfate (anhydrous) 28.4 Sodium chloride 23.5 Tetrasodium pyrophosphate (anhydrous) 23.5 Sodium dodecyl benzene sulfonate 2.9 Optical dye (same 'as Example I) 0 .10 White mineral oil 0.75

Color (a copper phthalocyanine type blue pigment to color the product light blue) 0.25

The foregoing ingredients are mixed, ground and employed as described above in Example I, with substantially comparable results as regards stability, washing and bleaching action.

Example VI Percent 1,3-dichloro-5,S-dimethylhydanto-in 7.5 Sodium toluene sulfonate 5.0

Sodium monoglyceride sulfate of coconut oil fatty acids (31% active ingredient) 25.0 Tetrasodium pyrophosphate (anhydrous) 25.0 Fluorescent dye (same as Example I) 0.13 White mineral oil 0.75 Heliogen blue 0.12 Sodium sulfate (anhydrous) 53.5

100 parts of the aforesaid composition in dry finelydivided form are tumbled in a rotating drum to bring about a homogeneous blending of the several ingredients thereof, whereupon the powdery composition is sprayed with 16 parts of water while agitation in the rotary mixer is continued. In this way minute beads of the product are formed .while mixing. The product does not become sludgy or liquid, and thefinal product is dry to the touch, and as such is ready for packaging. The stability, washing and bleaching action of this product is substantially comparable to that of the previous examples, having due regard as to the bleaching action ,to the lower available chlorine content of the composition which in this instance is about 4.7%

Example VII A spray-dried solid bleach composition is prepared by spraying a mix having the following composition:

Sodium alkyl benzene sulfonate base refers to a mixture of water sodium sulfate (6%) and sodium dodecyl benzene sulfonate (44%), the alkyl radical being a propylene tetramer. The hydantoin compound is used in this example as supplied by the manufacturer, no mechanical adjustment of particle size being made.

The pyrophosphate and water are mixed first, then the surface-active materials and sodium sulfate are added, and a uniform mix prepared. The temperature of the mix is maintained at 130-140" F. The hydantoin compound is added last and mixed for a minimum period (e.g., two minutes) so as to avoid decomposition thereof. The mix is thereafter spray-dried in .acountereurrent type tower using air at an initial temperature of about 340 F., it being desirable to dry as rapidly and at as low a temperature as possible to minimize decomposition of the hydantoin. The finished product contains 3% moisture, and is as stable when packaged as a granulated-type composition. The available chlorine of the product is 3.32% on a dry basis (equivalent to 4.9% of the hydantoin compound of 68% available chlorine). In this manner one obtains spray dried beads of a solid bleach composition having the following range of particle sizes.

U.S. Sieve Series:

10 (2.00 mm. opening) None retained. 20 (0.84 mm. opening) 3% max. retained. (0.250 mm. opening) 60% to retained. (0.149 mm. opening) 10% to 25% max.

. passed.

Normally, those partiqles passing through the 100 mesh screen are considered undesirable fines, not included in the final composition as prepared for market.

Example VIII I Another spray-dried product was prepared by admixing the following ingredients to yield a slurry having about 71-72% solids:

' Percent Sodium dodecyl benzene sulfonate slurry 7.55 Sodium toluene sulfonate slurry 7.85 Tetrasodium pyrop-hosphate 16.4 Sodium sulfate 41.83 Water 19.65 1,3 -dichloro-5,5-dimethylhydantoin 6.64 Fluorescent dye 0.08

This composition, analyzed on the dry basis and on the product basis (with 8% moisture), approximates the following:

Ingredients Dry Basis Product of Sodium dodecyl benzene sulronate, percerr 3. 953 3. 637 Sodium toluene sulionate, percent 4. 964 4. 567 Tetrasodium pyrophosphate, pereent 22. 892 21.062 Sodium sulfate, percent 58. 81 54. 104 Water, percent 0.000 8.000 1,3-dichloro-5,5-dimethylhydantoin, percent 9. 269 8. 527 Flurorescent dye, percent 0. 112 0.108

The spray drying procedure described in the preceding example is essentially the same as that used in. producing the composition of the present example. It will be appreciated that the'moisture content of the spray-dried product may be varied from the 8% shown, such as for example within a range of about 3 to 8.5%, the available chlorine being as high as approximately 5.8% on the dry basis in the finished product.

Example IX This example is illustrative of a combined bleachingwashing composition made up by dry-blending the preferred actiye bleaching agent described above with a. commercial detergent composition available on the market, as follows: Y

. Percent 1,3-dichl0ro-5,5-dirnethylhydantoin 4.0 A commercial detergent composition 96.0

The commercial detergent composition just mentioned is in the form of spray-dried beads prepared from a crutcher mix having the following composition (dry basis):

The spray-dried beads in dry form are mixed in a powder blender with the 4% hydantoin ingredient for approximately one hour. The substantial homogeneity of the mechanical mixture thus produced may be checked by titration for available chlorine, performed upon small aliquot portions of the mixture. The mixture is ready for packaging at the end of the approximately one hour mixing operation, and gives substantially cleaner and whiter washes when used by the housewife than when the same commercial detergent composition is used alone.

While 1,3 dichloro-S,S-dimethylhydantoin has been specified in the foregoing examples as the preferred dichlorodialkylhydantoin, it will be understood that other members of this class of dichloro-di-lower-alkyl'hydantoins and mixtures thereof may also be employed. For example, methylene-bis- (N-chloro-S-5-dimethylhydantoin 1,3-dichloro-5-methyl-5-isobutylhydantoin; 1,3-dichloro- 5-methyl-5-ethyl*hydantoin; 1,3 dichloro-5,5-diisobutylhydantoin; 1,3-dichloro-5-methyl-5-n-amylhydantoin, and the like may be employed with generally similar results.

When employing the tumbling-mixing method of the present invention in the presence of added moisture as described above (Example VI) the amount of moisture may be varied appreciably from the 16% ratio there shown, depending in part upon the particular composition undergoing processing. Quantities of moisture varying from about to 20%, based on the dry weight of the ingredients of the mix, can 'be employed, it being a simple matter in any given instance for the operator to determine the particular ratio that gives optimum results for the given composition, such as for example by performing a trial run upon an aliquot portion thereof. It is believed that the function of the added moisture is to effect a recrystallization of the ingredients of the composition, or at least of certain of them, but this phase of the invention is not to be regarded as limited by any such theory. In point of fact, this method appears to effect a recrystallization of the builder components of the composition as well as a desirable pelletizing of the entire com-position.

Various kinds of surface-active agents may be employed but it is preferred to employ bleach-stable surface-active agents of the anionic type although in certain circumstances surface-active agents of the non-anionic type may also be employed. A preferred surface-active agent is sodium higher alkyl benzene sulfonate although sodium lower alkyl naphthalene sulfonates, sodium dodecyl sulfate and various other alkali metal alkyl sulfates, aryl sulfonates and alkaryl sulfonates and the like may also be employed. These surface-active agents may be present in the composition to the extent of about 2 to 40%, depending in part upon the principal use for which the composition is intended. For example, where bleaching is the primary objective the surface-active agent content may be kept at the low end of this range, e.g., from about 2 to 10%. Where an all-purpose composition is desired, i.e., one which will be particularly effective for both bleashing and washing, the content of this type of agent should be raised to from about 10 to 40%, and where especially high emulsification power is required (as in washing operations where conditions of high grease content are encountered) the surface-active agent content should be kept at least as high as 30% of the composition and preferably nearer to 40% or even higher.

Suitable dyes and pigments may also be incorporated in small amounts in these compositions in order to impart.

pleasing colors to the compositions and/ or to the resulting solutions while being used and/ or to impart an optical bleaching effect to the textile materials undergoing treatment. For example, instead of the fluorescent dye mentioned above, one may employ other optical bleaches.

A small amount of a highly refined white mineral oil may be incorporated as an anti-dusting agent when the composition is made up in an extremely finely divided form. The particle sizes may vary over rather wide limits, ranging from definitely granular sizes (e.g., such as are obtained when spray-drying or pelletizing is resorted to) down to a very finely divided powder in which the bulk of the material is present in sizes ranging from about 5 to 50 microns. The particles produced by pelletizing and spray drying differ not only in size from mixtures of finely divided dry powder but also in the fact that each particle of spray dried or pelletized product is practically of the same composition as every other particle since all the particles are either formed from a homogeneous slurry in spray drying or by agglomerating a more or less uniform mixture of all the ingredients in more finely divided form into larger particles in pelletizing. On the other hand, in a mixture of dry powders the particles of each ingredient are distinct from the particles of every other ingredient with which they are simply more or less uniformly blended. Generally, the physical form of the product in which all of the particles are of practically the same composition, as obtained by spray drying, pelletizing, and like procedures, is preferred to a blend of dry powders of individual ingredients.

The compositions according to the present invention may also'desirably include certain additives whose primary function is to stabilize and/ or control the foaming properties of the composition. Such additives are higher fatty alcohols such as lauryl alcohol or alcohol mixtures derived by reduction of coconut oil fatty acids and higher fatty amides such as the monoethanolamide, diethanolamide and isopropanolamide of higher fatty acids such as lauric and myristic acids. This type of additive is especially desirable for use in conjunction with compositions which are intended primarily for washing purposes, wherein the hydantoin ingredient is present to a relatively lesser extent as a bleach ingredient.

The textile materials upon wihch the compositions of the present invention are particularly effective include fabrics of cotton, linen, synthetic fibers, and the like.

What is claimed is:

1. As a new composition of matter, a solid textile bleach composition in subdivided form comprising 1,3- dichloro 5,5 di-lower-alkyl-hydantoin in sufficient proportion to exert a distinct bleaching function and at least about 10% by weight of the composition of material from the group consisting of water-soluble molecularly dehydrated alkali metal phosphate salts, alkali metal silicates and fully neutralized alkali metal carbonates, said composition being characterized by an initial pH of at least 7.5 and by its ability to preserve whiteness of cotton on repeated bleaching treatments.

2. As a new composition of matter, a solid bleach composition as set forth in claim 1 which also contains a surface-active agent.

3. As a new composition of matter, a solid bleach composition as set forth in claim 2 in which all of the particles are of practically the same composition.

4. As a new composition of matter, a solid composition in the form of particles comprising about 5% to 15% of 1,3-dichloro-5,5-dimethylhydantoin, about 10% to 40% of water-soluble molecularly dehydrated alkali metal phosphate salt, about 2% to 40% by weight of alkali metal alkaryl sulfonates, vand the balance principally other alkali metal salts, the composition yielding aqueous solutions having an initial pH of at least 7.5.

5. A dry bleaching composition comprising 1,3-dichloro-5,5-dimethyl hydantoin and at least 10% sodium tripolyphosphate based on the weight of the composition.

6. As a new composition of matter, a solid textile bleach composition in subdivided form comprising about 1% to 30% of l,3-dichloro-5,5-dimethyl hydantoin, about 2% to 40% of bleach stable anionic surface active agent, about 10% to 40% material from the group consisting of alkali metal pyrophosphates, metaphosphates, tiripolyphosphates, tetraphosphates, silicates and fully neutralized carbonates, and the balance principally other alkali metal salts, the composition yielding aqueous solutions having an initial pH of at least 7.5.

References Cited by the Examiner UNITED STATES PATENTS 1,894,207 1/1933 Taylor 81 08 1,894,539 1/1933 Mirau 8108 1,988,991 1/ 1935 Albertshauser 8-108 2,034,361 3/1936 Sutton 25299 2,308,992 1/ 1943 Mertens 25299 2,367,771 1/1945 Hampel 8108 2,417,570 3/1947 Rogers 8l08 2,423,452 7/1947 Holuba 252161 2,430,233 11/1947 Magill 252187 2,430,674 11/ 1947 Hampel 8108 2,534,781 12/1950 MacMahon 8-108 2,607,738 8/1952 Hardy.

2,634,238 4/1953 Soule 25299 2,730,428 1/1956 Lindner 8108 2,863,800 12/1958 Gottfried 8108 1 0 OTHER REFERENCES Elod et al: Melliand Textilber, vol 18, p. 64 (1937). I

Industrial and Engineering Chemistry, November 1948, pp. 2054-2059.

Reference Data, Textile World, p. 60, November 1953.

NORMAN G. TORCHIN, Primary Examiner.

DONALD J. ARNOLD, CARL F. KRAFFT MORRIS O. WOLK, Examiners.

WILLIAM B. KNIGHT, F. CACCIAPAGLIA, H. WOL- MAN, I. CANNON, Assistant Examiners. 

4. AS A NEW COMPOSITION OF MATTER, A SOLID COMPOSITION IN THE FORM OF PARTICLES COMPRISING ABOUT 5% TO 15% OF 1,3-DICHLORO-5,5-DIMETHYLHYDANTOIN, ABOUT 10% TO 40% OF WATER-SOLUBLE MOLECULARLY DEHYDRATED ALKALI METAL PHOSPHATE SALT, ABOUT 2% TO 40% BY WEIGHT OF ALKALI METAL ALKARYL SULFONATES, AND THE BALANCE PRINCIPALLY OTHER ALKALI METAL SALTS, THE COMPOSITION YIELDING AQUEOUS SOLUTIONS HAVING AN INITIAL PH OF AT LEAST 7.5 